Date: Wed, 9 Jul 2014 20:47:54 +0300 From: Sami Halabi <sodynet1@gmail.com> To: Julian Elischer <julian@freebsd.org> Cc: freebsd-net@freebsd.org, Niu Zhixiong <kaiaixi@gmail.com> Subject: Re: A question on modifying packet. Message-ID: <CAEW%2BoganLM=as%2Bb2GOsKbqbsjw95uMnfVKVj09ZdFndvO8V21Q@mail.gmail.com> In-Reply-To: <53BD7317.9030008@freebsd.org> References: <CAOENNMA-%2B6P2tT3JTusH3Q8Qz4O7XnAc0ZEjVRqxU3W342sp%2Bg@mail.gmail.com> <53BD7317.9030008@freebsd.org>
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use netgraph.
In theory it should work.. in practice It worked for me once, but couldn't
repeat the success.
See ng_patch. Here is the code i tried:
kldload ng_patch
kldload ng_ipfw
/usr/sbin/ngctl -f- << SEQ
mkpeer ipfw: patch 300 in
name ipfw:300 src_dst_chg
msg src_dst_chg: setconfig { count=3D2 csum_flags=3D1
ops=3D[ \
{ mode=3D1 value=3D0xc0a8e609 length=3D4 offset=3D=
12 } \
{ mode=3D1 value=3D0xc0a8e680 length=3D4 offset=3D=
16 } ] }
SEQ
/sbin/ipfw add 600 netgraph 300 log ip from any to 239.0.0.19 dst-port 1234
in via vlan999
Sami
On 7/9/14, 1:01 PM, Niu Zhixiong wrote:
> Hi, all
> I have only one NIC. I want to capture packets from one certain ip addres=
s
> and change the both src and dst addresses and forward to other destinatio=
n
> via the same NIC. It is possible? Is there any library to help me do this=
?
>
there is no library, but look at how natd does this using divert sockets.
>
> Regards,
> Niu Zhixiong
> =EF=BC=8D=EF=BC=8D=EF=BC=8D=EF=BC=8D=EF=BC=8D=EF=BC=8D=EF=BC=8D=EF=BC=8D=
=EF=BC=8D=EF=BC=8D=EF=BC=8D=EF=BC=8D=EF=BC=8D=EF=BC=8D=EF=BC=8D
> kaiaixi@gmail.com
> _______________________________________________
> freebsd-net@freebsd.org mailing list
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> To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org"
>
>
>
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